Production of stereotypic printing-plates.



" i (i0rJlWirzkk gig A C. WINKLER. v PRODUCTION OF STEREOTYPIC PRINTING PLATES. APPLICATION FILED FEB. 25. 1915.

1,204,107 I Patented Nov. 7,191

WITNESSES.

INVENTO/f' ATTORNEYS Y cant WINKLERJOF BERN, swrrznnnann.

PRODUCTION OF STEREQTYPIC, PRINTING-PLATES.

To all whom it may concern: 1 Be it known that I, CARL WINKLER, a citizen of the Swiss Republic, residing at Bern,

in the Swiss Republic, have invented new j the apparatus is shown.

and usefullmprovements in the Production of Stereotypic Printing-Plates, of which the following is a specification.

, Heretofore it was usual, in casting stereotypic printing plates, to heat the mold to a temperatureof about 150 C. before cast ng.

On pouring in the molten lead having a temperature of about 300 C. the mold was. naturally still further heated by this metal, and it was then soon cooled down again by cold water. As a consequence themold-was subjected to many considerable changes,

- which necessarily bad a bad influence on the plate being cast. treat both parts of the mold, that is the part Further, it .was usual to carrying the matrix and the part forming the back of theplate, uniformly, by causing cooling Water of the same temperature to" pass through said. parts.

N 0w, in order to produce (plates characterized bygreater accuracy an reliability than those heretofore used, the parts. of the mold are separately'treated according: to the present invention, and indeed in such a manner that the temperature of each art-separately is kept as uniform as possile during the entire casting process. Forexample, the part. carrying the'matrix .(thus in the case of curved plates mostly the cope or bed) is to be kept permanently at a temperature of about 150 0., and the other part at about.

100 0., during the entire process. Trial has shown that plates produced under these conditions are much more accurate than those produced heretofore, so that such plates are particularly suitable for multiple color prlnting.

For heating the parts of the mold, steam will be found suitable, which may be caused to circulate through channels specially provided for the purpose. This steam, therefore, does not only serve to heat the mold,

but also to prevent said mold from getting hotter when the molten metal is poured in, the steam taking up and carrying off all such excess heat. i Instead of steam any other suitable agent such as hot water, air, gas, oil, or the like,

may be employed.

If steam is used forheating the mold the apparatus shown on the drawing may be used with advantage. In this apparatus Specification of Letters Patent.

Patented Nov, 7, 1916.

Application filed February 25, 1915. 7 Serial No. 10,598.

' the waste gases of the furnace used to melt The metal to be melted is contained in the crucible a, which is heated by the fire on the grate b. The hot gases leave the furnace through the opening 0 and pass into the steam generator d, where they pass through t e pipes contained therein and finally es-.

cape through the flue e or the like. The lead.

fumes from the crucible are led ofl through the hood'f and pipe 9 A door'i is hinged to. swing against the lower ends of the pipes. of the generator as shown in dotted lines and when in this position the gases passing oil from the furnace are caused to pass through a jacket provided between an outside mantle and the boiler instead of through the whole boiler itself.

In this. case no steam is developed, but the water contained in the boiler is only heated somewhat. The steam generated in the boiler (Z is conducted through thepipe k having a cock k to a steam chamber Z in thebed of the mold. The full pressure of the steam acts in the steam chamber and as a consequence a temperature corresponding to the pressure, for example about 150 degrees C., is maintained in the bed. A branch pipe leads from the pipe k? to a chamber of the drag 2 of the mold, and in said branch pipe is a throttling valve in which reduces the pressure of the steam to about atmospheric pressure and the steam at this pressure enters the chamber of the drag, and is maintained' therein at about 100 degrees FC.

Over the boiler there is a water receiver h which is arranged in such a way that in every position of the door 71 it'is always furnace. This hot water can be used for one or both parts of the mold.

\Vhen the door 2' is open the gases pass from the grate 6 through the opening c and simultaneously through the pipes 03 and between the boiler and .the outer casing. As the space between thezboiler and the outer mantle is narrow, and as the top of this space is not open all around, but only for a part of its circumference, there is some little resistance to the passage of the gases so that these gases also descend somewhat 'after passing through the opening 0 and escape into the pipes d in which 'therefi'sgalso a heated by the gases passing off from the draft If the door 2' is closed it is evident that the gases cannot enter the pipes d, but

can only-pass, between the boiler and the outer mantle; the jacket, although not necessarily open all around, is at least provided with openings to enable the products of combustion to pass through.

The grate in the fire-box in which the door 1' swings may be adapted to be taken out in order to enable the door to beclosed.

It is to be understood that the tempera-- tures given above are not binding, but are only to be Considered as examples.

'hat I claim and desire to secure by Letters Patent of the United States is 1. The prowess for casting stereotype plates which consists in kee ing the parts of the mold at approximatey constant but different temperatures during the time immediately preweding the flowing in of the molten metal, during the flowing in of the molten metal and during the cooling of the plate, by conducting a thermic agent of thermic a at of lower constant temperature through t e other part of the mold, substantially as and for the purpose set forth.

The prwess of casting stereotype plates, consisting in subjectin the parts of the mold, prior to the int action of the metal thereto, to the action of a heating medium to raise the part carrying the matrix to a temperature greater than theother art, and maintainin the parts of the mo d at constant but di erent temperatures throughout the castin operation.

In testimony whereof I ve signed my name to this specification in the presence of two subscribing witnesses.

CARL WINKLER.

' Witnesses:

J. M. Bowcocx, Y M. Bmscmon.

higher constant temperature through the "jacket of the part carrying the matrix and a 

